Valhall adds float color target support in hardware, including hardware
blending. This commit just adds the XML and doesn't enable it in the C
code. Annoyingly, even though there's enough bits to do otherwise, the
hardware re-interprets the color (writeback) format field in the render
target descriptor based on the internal format. The easiest way to
handle this in the XML is to just have two different enums and fields in
the Render Target structs which alias. This seems to be the least
duplication while still encoding the necessary information.
Reviewed-by: Aksel Hjerpbakk <aksel.hjerpbakk@arm.com>
Reviewed-by: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/39171>
aac927aa15